Cryptographic security chips have been developed as embedded systems with complicated software and hardware, with an improvement of SOC design and technology. However, security problems are occurred since the cryptographic security chips are involved with encryption algorithms and secret keys which may be attacked by a cracker by means of reading, analyzing and dissecting, including ultrahigh or ultralow clock frequency attacks, physical detection attacks, energy attacks, side channel attacks or DPA attacks, etc.
Nowadays, a chip is usually encrypted by means of a fixed encryption algorithm, a fixed secret key or an ID number of the chip. Thus crackers only need to crack a matrix chip or delete the binding of the ID number of the chip under a help of software to obtain the encryption algorithm and the secret key of the matrix chip, thereby obtaining all secret keys of the batch chips corresponding with the matrix chip.
Most of the cryptographic security chips have a built-in encryption algorithm by designing an AES module or a 3DES encryption module, etc. The same secret key is utilized and solidified into the chip when the chip is designed. For the same matrix chip, the same encryption algorithm and the same secret key are applied.
More importantly, the matrix chip may be utilized in different applications. That is to say, crackers can obtain all applications of the matrix chip once the matrix chip is cracked successfully. By this token, cracking the cryptographic security chips nowadays is easy and low-cost for crackers.